Sunday
Arrival at castle after 4pm, registration and catering dinner
Monday
Time
Speaker
Title
9:00
Welcome, Intro and Logistics
Chair: Fabrizio Arrigoni Battaia
9:15
Angelo Ricarte
Accretion and Feedback at the Event Horizon
9:40
Hyerin Cho
Bridging Scales in Black Hole Accretion and F
Title: Bridging Scales in Black Hole Accretion and Feedback: Relativistic Jet linking the Horizon to the Host Galaxy Abstract: Simulating black hole (BH) accretion and feedback from the horizon to
galactic scales is extremely challenging, as it involves a vast range
of scales. For the first time, our multizone method has successfully
achieved global dynamical steady-states of hot accretion flows in
three-dimensional general relativistic magnetohydrodynamic (GRMHD)
simulations by tracking the bidirectional interaction between a
non-spinning BH and its host galaxy. In this talk, I present
simulations of strongly magnetized Bondi accretion for various Bondi
radii, RB ≈ 400, 2e3, 2e4, 2e5 rg, for both non-spinning (a=0) and
spinning (a=0.9) BHs. We find that the BH accretion rate is suppressed
with respect to the Bondi rate, depending on the Bondi radius RB.
However, despite some variability, the time-averaged feedback
efficiency is independent of RB, where the efficiency is η∼30% for
a BH spin a=0.9. This suggests that BH feedback efficiency in hot
accretion flows is mainly governed by the BH spin (a) rather than by
the galactic properties (RB). From these first-principles simulations,
we provide a feedback subgrid prescription for cosmological
simulations and compare it with the BH models used in cosmological
simulations.
10:05
Nicholas Kaaz
Strongly magnetized accretion in quasars
10:30
Coffee Break
Chair: Ulrich Steinwandel
11:15
Tim Heckman
The Role of Radio Jets in the Evolution of Gal
11:40
Leah Morabito
The hidden AGN population: a novel radio pers
12:05
Gaoxiang Jin
An IFU View on Star Formation, Outflows, and
Title: An IFU View on Star Formation, Outflows, and Gas Excitation across the AGN Population Abstract: We study the spatially resolved star formation, gas excitation, and outflow properties of ~1500 active galactic nuclei (AGN) in the full MaNGA survey. These AGN are classified into Type 1, Type 2, infrared, and radio AGN based on their optical spectra, mid-infrared colours, and radio photometry. We estimate the AGN contribution to emission lines, infrared, and radio luminosities to trace the power of the narrow or broad line regions, the torus, and the radio jets of the AGN respectively. Compared to mass-matched control samples, we find enhanced nuclear star formation in infrared, Type 1, and Type 2 AGN, and suppressed star formation in radio AGN. Outflow features are also more prominent in infrared and Type 1 AGN, as well as in inner radial bins. Stronger gas excitation is found in all AGN populations, especially within the central kpc region. Stronger AGN are have more prominent effects. Our results support a scenario that as high Eddington ratio AGN with strong emission line regions and dust torus evolve to low accretion mode radio AGN, while the host galaxies tend to transit from a nuclear starburst stage to a quiescent phase.
12:30
Lunch
Chair: Chian-Chou Chen
14:00
Jay Gonzalez Lobos
QSO MUSEUM III: The circumgalactic Lyman-alp
14:25
Mandy Chen
Turbulence Drivers in Quasar Halos: Insights
14:50
Bo Peng
Resolving Warm-to-Cold outflows around a Q
Title: Resolving Warm-to-Cold outflows around a QSO at Redshift 2.8 Abstract: Understanding the physical properties and phase interactions within galactic outflows remains a major challenge. In this talk, I will present results from a detailed study of the multi-phase outflows in the z ~ 2.8 submillimeter galaxy-quasar system SMM J02399-0136, a uniquely rich environment for exploring large-scale feedback. Leveraging high-resolution observations from HST, JWST, and ALMA/ACA across a suite of emission lines—including Ly⍺, [O III], [C II], [N II], [C I], and CO—we map a complex structure of ionized, neutral, and molecular gas extending from the QSO out to 60 kpc. These observations reveal jet-ISM interactions, collimated outflows, filaments in CGM, with evidence for periodic feedback, turbulence, strong UV/optical line cooling. I will discuss how multi-line diagnostics constrain key physical conditions—such as density, ionization state, and chemical abundance, and highlight how deep imaging enables new insights into feedback processes at galactic scales.
15:15
Coffee Break
Chair: Chian-Chou Chen
16:00
Sylvain Veilleux
The Impact of the AGN on the Multiphase Envir
16:25
Martin Bourne
Simulating supermassive black holes: from ev
16:50-18:00
Discussion (different meeting rooms)
18:30
Dinner
Tuesday
Time
Speaker
Title
Chair: Bo Peng
09:00
Erini Lambrides
Missing the Forest for the Seeds: Uncovering
Title: Missing the Forest for the Seeds: Uncovering Representative Black Hole Growth at Early Times Abstract: With the launch of JWST, we are uncovering a supposed extreme over-abundance and over-massiveness of z>4 supermassive black holes. From X-ray to Radio, expectations built off of pre-JWST predictions fail to reproduce the observed accreting black hole signatures (or lack thereof) of these newly discovered sources. We are potentially on the brink of a paradigm shift in early BH evolution -- but to robustly test and potentially break accepted paradigms, we need deeper observations, with greater resolution, and to move beyond single wavelength regime approaches. In this talk I will highlight my recent works that are centered on detailing the physical nature of the early AGN candidates discovered with (and without) JWST. I will describe our study on physically connecting the inconsistencies between predictions and multi-wavelength observations of JWST AGN identified via their broadened Ha emission and show how the radiative inefficiency predicted in some models of super-Eddington accretion can self-consistently explain the lack of X-ray, UV line, & rest-NIR flux exhibited in these sources — implying rampant BH growth in the early Universe. These results also have implications on our ability to robustly measure BH mass via single-epoch approaches. I will also discuss our recent ultra-deep, medium resolution JWST observations of a z~7 “Little Red Dot”. We measure significant Balmer absorption within multiple Balmer emission components, and will present our robust constraints on the source of the absorption. We also uncover diverse forbidden iron emission, including for the first time, a potential coronal line detection at these epochs. While these new sources identified with JWST are exciting, they may only represent the tip of the iceberg of the total AGN demography at early times. Heavily obscured AGN, whose broad-line features are so attenuated they are absent, are predicted to dominate z > 4 BH populations. I will discuss our novel selection algorithm in uncovering the most obscured AGN with JWST imaging/spectroscopy and deep multi-band radio coverage. We find these sources live amongst the most massive, star-forming galaxies of their epoch, and I will discuss the implications these results have in the context of feedback and the high-z AGN candidates solely identified with JWST.
09:25
Roberto Maiolino
The population of infant black holes and their
9:50
Teodora-Elena Bulichi
Early supermassive black hole growth with J
Title: Early supermassive black hole growth with JWST and on-the-fly radiative transfer cosmological simulations Abstract: The presence of supermassive black holes (SMBHs) with masses ≳ 10⁹ M⊙, within the universe’s first billion years, confirmed by quasars’ rest-frame ultraviolet and optical spectra represents one of the biggest challenges for models involving their growth. Under standard black hole growth assumptions, forming such SMBHs requires quasar lifetimes of order tQ ∼ 10⁸–10⁹ yr. However, studies involving quasars’ proximity zones suggest much shorter lifetimes, as low as tQ ∼ 10⁴–10⁵ yr (e.g., Eilers et al. 2017). To address this discrepancy, I have developed a new set of cosmological simulations incorporating on-the-fly radiative transfer, capable of reproducing the hydrodynamic response of intergalactic medium to the inhomogeneous photoheating and of modeling in detail the galaxy population and escape of ionizing radiation. This framework enables a self-consistent treatment of SMBH growth through multiple accretion episodes, distinguishing recent quasar activity from the total lifetime and offering a potential resolution to the tension posed by short quasar lifetime estimates. Moreover, I will talk about my efforts of quantifying early obscured SMBH growth using the MEOW JWST program, which can give raise to small quasar proximity zones, that imply short quasar lifetime estimates.
10:15
Sunmyon Chon
The rapid emergence of overmassive BHs and
10:30
Coffee Break
Chair: Jay Gonzalez Lobos
11:15
Jan-Torge Schindler
Placing Supermassive Black Holes in Perspect
Title: Placing Supermassive Black Holes in Perspective - Environments and Galaxy Clustering around Two Quasars and a Little Red Dot at z~7.3 Abstract: The clustering of galaxies around high-redshift quasars, or active galactic nuclei (AGN) in general, provides us with a way to connect the growth of their supermassive black holes (SMBHs) to the formation of large scale structure in our Universe. It therefore offers critical information to understand the early rise of billion solar mass SMBHs by connecting them to their birthplaces in the cosmic web. Sensitive near-infrared spectroscopy obtained with the James Webb Space Telescope (JWST) now routinely unveils distant, z>6 galaxies, enabling AGN-galaxy clustering measurements well into the epoch of hydrogen reionization. With the Cycle 1 JWST program “Towards Tomographic Mapping of Reionization Epoch Quasar Light-Echoes” we have surveyed two z>7 quasar fields for galaxies with NIRSpec/MSA spectroscopy, discovering a z~7.3 AGN, which belongs to the highly debated class of “Little Red Dots” (LRDs). I will present a spectroscopic view of the environments of the two quasars J1007+2115 (z=7.5) and J0252-0503 (z=7.0), including a first look at quasar-galaxy clustering at z>7. Furthermore, I will discuss the discovery of the LRD at z~7.3 with an intrinsic quasar-like bolometric luminosity and a SMBH mass of 100 Million solar masses. Most notably, this object is embedded in an overdensity of eight nearby galaxies, allowing us to also calculate the clustering of galaxies around LRDs at these early times. In closing, I will highlight the future potential for z>7 quasar-galaxy clustering with new quasar discoveries from Euclid mission.
11:40
Shanquan Gui
Galaxy environment around quasars near 1
12:05
Chian-Chou Chen
Tracing the Dusty Environments of AGN at C
Title: Tracing the Dusty Environments of AGN at Cosmic Noon Abstract: AGN and dusty star-forming galaxies, both hosted by massive halos, are thought to co-evolve throughout much of cosmic history—most prominently at cosmic noon, the peak epoch of black hole growth and stellar mass assembly. Yet, key questions remain unresolved, including how this co-evolution proceeds and how AGN and galaxies influence one another’s growth. In this talk, I will present new ALMA results targeting SCUBA-2–selected dusty galaxies around quasars at z~2–3 hosting Lyman-alpha nebulae. We find that spectroscopically confirmed dusty galaxies linked to these quasars on Mpc scales show dust and gas properties comparable to those in the field. However, combining our findings with results from the literature, we identify a significant reduction in gas fractions among galaxies within the quasars’ virial radii, suggesting that massive dusty galaxies are affected by their host quasars primarily on halo scales. Finally, stacking analyses reveal that the spatial distribution of dusty galaxies resembles filamentary structures with characteristic widths of 3–5 Mpc, consistent with model predictions for thick cosmic filaments
12:30
Lunch
Chair: Mandy Chen
14:00
Nianyi Chen
Catching Massive Black Hole in Pairs: From D
14:25
Eileen Herwig
The circumgalactic medium and Mpc-scale gal
14:50
Carlos De Breuck
Gas-poor AGN hosts surrounded by gas-rich m
Title: Gas-poor AGN hosts surrounded by gas-rich mergers Abstract: Gas-poor AGN hosts surrounded by gas-rich mergers" "Mergers are important in stellar mass buildup and triggering feedback, especially in the high-redshift universe. High-z radio galaxies (z > 2, radio loud type-2 quasars) are known to trace
the dense protocluster environment and be hosted by M_* ~ 10^11 M_sol galaxies. They are often surrounded by halos on scales of tens of kpc, but high-resolution observations within the central kpc have been lacking.
I will present our matched ~0.1"" resolution ALMA+JWST/NIRSpec IFU view around the center of four z = 3.5 radio AGN. We ubiquitously discover ~12 companion systems at distances of < 18 kpc using two independent methods: (i) peculiar [OIII] 5007Å kinematics; (ii) [CII] 158µm emission. We estimate that these systems have M_dyn~10^9-11 M_solar, which indicates a minor merger scenario.
Surprisingly, all [CII] emitting blobs that were detected are offset from the AGN position, suggesting that cold gas does not reside in the massive host. Our results indicate that these mergers could be the trigger of the most powerful AGN jets at the beginning of Cosmic Noon. They bring gas to the supermassive black holes in the gas-poor host and ignite the AGN feedback on scales of tens of kpc, which the hosts themselves are already on the road to being quenched.
We also find that the companions can impact the propagation of the jet, e.g., by deflecting the jet. Overall, they play an important role in the evolution of the progenitors of massive galaxy clusters.
15:15
Coffee Break
Chair: Darshan Kakkad
16:00
Jelena Ritter
Multiphase gas reservoirs around z~3 quasars
Title: Multiphase gas reservoirs around z~3 quasars and the impact of feedback from galaxy to halo scales Abstract: Extended Ly-alpha nebulae observed around quasars trace the cool gas within the multiphase circumgalactic medium and can provide key insights into the complex interplay between gas dynamics and active galactic
nuclei (AGN) feedback. However, the connection between this cool phase and the cold molecular gas around the host galaxies remains largely
unexplored. In this talk, I leverage ALMA CO(4–3) observations of 37 quasars at z ~ 3 — all of which have been previously mapped in Ly-alpha with VLT/MUSE — to investigate the relation between the CO emission, and hence the molecular gas content, and halo properties. I show that systems with higher black hole mass and lower Eddington ratio exhibit higher CO detection rates while also demonstrating lower Ly-alpha surface brightness. This result suggests that radiative feedback regulates cold gas survival in dusty, gas-rich environments, consequently affecting the reprocessed Ly-alpha emission
from the halo. Additionally, as quasars trace overdensities, I report on the incidence and properties of CO emitting companions and discuss any
evidence of gas depletion when approaching the quasar massive halo. This investigation aims to provide a deeper understanding of the connections between different gas phases, their relation to quasar properties, and the processes that govern the co-evolution of galaxies and black holes.
16:25
Eunchong Kim
Using Polarization to Uncover the Lya Emission
Title: Using Polarization to Uncover the Lya Emission Mechanism in Lya Nebulae Abstract: Lyman-alpha (Lyα) nebulae are immense (~100 kpc) glowing gas clouds located in the distant universe, and the origin of their extended Lyα emission remains a mystery. Mapping their polarization offers critical insights, but imaging polarimetry to date has revealed polarization patterns that are difficult to interpret due to differences in the types and spatial configurations of their embedded sources. In this study, we more than double the sample size of polarization observations by targeting four additional Lyα nebulae: 4C41.17, SSA22-Sb3-LAB1, JACKPOT, and MAMMOTH-1, all of which host active galactic nuclei (AGN), from radio-loud to radio-quiet to type-I to type-II. Significant polarization is detected in three of these four nebulae, with polarization vectors distributed across the extended Lyα-emitting gas. In the two Lyα nebulae hosting radio-loud AGN, the polarization vectors exhibit a preferential alignment perpendicular to the radio jet direction, suggesting a scattering origin related to AGN outflows. In 4C41.17, JACKPOT, and MAMMOTH-1 (3/4 cases), the polarization strength shows a possible trend of increasing with radius. While the spatial patterns are complex and most large-radius measurements are upper limits, our results—together with previous work on three other targets—support the idea that scattering plays a key role in shaping the Lyα emission from these nebulae. Full interpretation requires direct comparison of these observations to radiative transfer models over a wide range of parameter space.
16:50
Davide Tornotti
Mapping the Cosmic Web in Lyα around Quasars
17:15
Discussion (Mandy Chen, Chian-Chou Chen, Michael Tremmel, Erini Lambrides)
18:30
Dinner
Wednesday
Time
Speaker
Title
Chair: Nicholas Kaaz
09:00
Andrew Fabian
Cooling flows in clusters, groups and ellipti
09:25
Kung-Yi Su
Bridging Scales: Coupling the galactic nucleus
09:50
Ulrich Steinwandel
Simulating the formation of the Coma cluster
Title: Simulating the formation of the Coma cluster Abstract: We present a suite of 50 high-fidelity simulations of Coma cluster analogues constructed from constrained initial conditions and evolved with the IllustrisTNG galaxy formation model. Regions predicted to form massive clusters comparable to Coma in mass and environment are selected and followed through cosmic time, producing realistic galaxy populations and intracluster medium properties. The ensemble captures both cosmic variance and uncertainties in the local initial conditions, providing a statistically robust framework for interpreting Coma in a cosmological context.
We focus on direct comparisons with observed thermodynamical profiles of the intracluster medium. Specifically, we extract X-ray surface brightness profiles and confront them with eROSITA measurements, as well as compute integrated Compton-y profiles for comparison with Planck thermal Sunyaev–Zel'dovich observations. In a second step, we systematically vary AGN feedback activity in order to probe how changes in energy injection impact these observable signatures. The simulations reproduce the broad shape and normalization of current observations, while highlighting the range of scatter expected from environmental, assembly history, and feedback variability.
Our results show that combining constrained cosmological initial conditions with state-of-the-art galaxy formation physics provides an effective strategy for generating targeted, observation-driven analogues of specific clusters. The resulting dataset offers a valuable resource for testing models of intracluster medium physics, evaluating the role of AGN feedback, calibrating scaling relations, and interpreting upcoming joint X-ray and Sunyaev–Zel'dovich observations of nearby massive clusters.
10:15
Eugene Churazov
Low-beta non-thermal filaments in galaxy clust
Title: Low-beta non-thermal filaments in galaxy clusters and the Galactic Center region Abstract: We argue that filaments with ordered magnetic fields supported by non-thermal pressure can provide a fast way of transporting relativistic electrons in galaxy clusters and other environments. In particular, along quasi-stationary filaments, electrons can propagate without experiencing adiabatic losses, and their velocity is not limited by the Alfvén or sound speeds of the ambient thermal plasma. This model predicts that along filaments that span significant pressure gradients, e.g., in the cores of galaxy clusters, the synchrotron break frequency should scale with the square root of the ambient gas pressure. The emission from such filaments should be strongly polarized due to the magnetic field being ordered along these structures. While some of these structures can be observed as ""filaments"", i.e., long and narrow bright structures, others can be unresolved and have a collective appearance of a diffuse structure, or be too faint to be detected, while still providing channels for electrons' propagation.
10:40
Coffee Break
Chair: Nianyi Chen
11:15
Akash Vani
Star formation and feedback (free) that shape
11:40
Guinevere Kauffmann
The Unusual Stellar Environments of some ne
12:05
Johannes Buchner
Data-driven galaxy-AGN co-evolution studies
Title: Data-driven galaxy-AGN co-evolution studies with eROSITA, Euclid and LSST Abstract: Galaxy evolution follows the tapestry set by cosmology, but is modulated by central supermassive black holes. Limited human lifetimes makes it complex to study the stochastic in- and outward gas motion from dark matter halos to near the event horizon. Nevertheless, the last few decades have revealed a probabilistic multi-dimensional interlink between AGN outflows, black hole mass, accretion, galaxy mass, star-formation, morphology, and obscuration. Degeneracies linger in the demographic evolution of black holes and their radiative processes, which are important to resolve if we want to precisely understand the cosmic mass outflow budget affecting galaxies and the intergalactic medium. The millions of AGN found photometric and spectroscopic surveys, including eROSITA, Euclid, LSST, SphereX, SDSS-V, DESI and 4MOST, hold the information to break these degeneracies if selection effects are addressed with scalable inference methods. First results on AGN-galaxy co-evolution with eROSITA include the discovery of abundant over-massive black holes at z<1, at odds with the interpretation of over-massive black holes as seed remnants and the tight correlations in current galaxy evolution simulations.
12:30
Lunch
Chair: Alessandro Lupi
14:00
Eckhard Sturm
Spatially resolved BLR measurements and weighi
14:25
Daniel Anglés-Alcázar
Modeling the multiscale physics of AGN across
14:50
Sarah Wellons
Modeling black hole and galaxy growth and q
15:15
Coffee Break
Chair: Kung-Yi Su
16:00
Yi Zhang
The Hot Circumgalactic Medium in the eROSITA A
16:25
Sebastiano Cantalupo
Illuminating the link between AGN growth and
16:50
Fabio Vito
Does overdense environment on Mpc scales en
Title: Does overdense environment on Mpc scales enhances SMBH growth at z=2-4? Abstract: The large-scale environment is one of the key drivers of galaxy evolution, but the link with SMBH growth, especially at high redshift, is so far poorly understood.
The densest regions at high redshift, i.e. galaxy ""protoclusters"", are characterized by huge gas reservoirs continuously infalling from the forming cosmic web, and high rates of galaxy interactions and mergers. These properties are thought to favor the triggering and sustaining of fast SMBH accretion in the galaxy centers, possibly enhancing the incidence of AGN in the structures. I will present recent results from an ongoing investigation of the AGN content of z=2-4 protocluster candidates, aimed to quantify the effect of the overdense environment on the SMBH growth at high redshift. We are using X-ray observations of protoclusters to identify securely AGN among the structure members, generally finding significant enhancements of the AGN incidence (i.e. factors of a few) and space density (i.e. few orders of magnitude) with respect to expectations from blank fields, especially at high luminosities. We are investigating the environmental effect by comparing the observational properties of galaxies and AGN in protoclusters derived from SED fitting with those of control galaxies in the field environment and with predictions from simulations like TNG and Magneticum.
17:15-17:45
Discussion (Daniel, Sophie, Sarah, Benny)
18:30
Bavarian Dinner
Thursday
Time
Speaker
Title
Chair: Jan-Torge Schindler
09:00
Thorsten Naab
Formation and growth of SMBH seed in dense st
09:25
Kohei Inayoshi
The Emergence of the First Massive BHs
09:50
Michael Tremmel
Massive Black Hole Growth in the Early Universe
10:15
Alessandro Lupi
Super-Eddington accretion and feedback in high
Title: Super-Eddington accretion and feedback in high-redshift quasar hosts Abstract: For more than a decade, observations of high redshift quasars up to z~7 have told us that massive black holes (MBHs) were already in place, with masses well above 10^9 solar masses, when the Universe was less than 1 Gyr old. Recent observations by JWST have shown that MBHs are ubiquitous above z=6, even in lower mass galaxies, and are typically overmassive compared to their galaxy host. These results significant challenged to our understanding of how these objects formed and evolved, in particular when we consider that the energy produced by the accretion process is released into the MBH surroundings, producing outflows that can potentially interact with the interstellar medium, regulating/quenching star formation, but also inhibiting further MBH accretion. Despite decades of research, an accurate description of the processes at play is still missing, because of the huge dynamic range and the approximate modelling in current simulations.
In particular, current studies suggest that, either i) the MBHs are already extremely massive at formation (M>10^5 Msun), or ii) they have to bypass an initially stunted growth (due to the strong impact of supernovae in the galaxy nucleus which significantly perturbs the inflowing gas).
An appealing way to overcome this issue is represented by relatively short phases of accretion above the Eddington limit. In my talk, I will present a recent effort at modelling in the most accurate way possible the evolution of MBHs in high-redshift quasars, including super-Eddington accretion and the associated feedback. I will first show how super-Eddington accretion phases can be sustained over relatively long timescales, producing MBHs consistent with current observations. Then, I will discuss how the inclusion of detailed non-equilibrium chemistry and thermodynamics in our simulations allowed us to describe the multi-phase nature of accretion-powered winds and jets and the ISM emission properties. Finally, I will discuss how high-redshift sources that appear completely different, as Little Red Dots, quasar hosts, and quenched galaxies, might simply represent different evolutionary stages of massive galaxies in the young Universe.
10:40
Coffee Break
Chair: Matthew Smith
11:15
Benny Trakhtenbrot
Puzzling Types of Transient Phenomena from Acc
Title: Puzzling Types of Transient Phenomena from Accreting Supermassive Black Holes Abstract: A growing number of transient phenomena in galaxy nuclei have recently begun to shed new light on SMBH demographics and the physics of gas accretion onto these objects, tracing events where this accretion has drastically intensified, diminished, and/or otherwise disturbed, over surprisingly short timescales. These phenomena include “changing look AGN” and other, poorly understood flares from accreting SMBHs that show rare emission features driven by extreme UV radiation. I will discuss some of these new classes of transients, focusing on new results obtained with large time-domain surveys and responsive, multi-wavelength follow-up observations. While these events observationally differ from the (stellar) tidal disruption events known to date, the physics behind them may be interlinked. Together, these transient phenomena can greatly advance our understanding of SMBH accretion, teach us how and why SMBHs turn their accretion “on” and “off”, and reveal the sought-after signs of super-Eddington accretion. I will also mention how new & upcoming surveys are going to discover & survey many more SMBH-related transients.
11:40
Scott Hagen
Understanding the Inner Structure of AGN Thro
12:05
Sophie Koudmani
Elucidating the black hole-galaxy connection:
Title: Elucidating the black hole-galaxy connection: insights from AGN accretion disc modelling Abstract: JWST has made major strides in uncovering early supermassive black holes, extending observed samples to lower masses and luminosities compared to previous quasar surveys at similar redshifts. This includes a population of overmassive black holes, compared to the local scaling relations, which may have a significant impact on the baryon cycle of their host galaxies. I will present a new set of large-volume cosmological simulations testing various seed masses and models for feedback from active galactic nuclei (AGN), with a specific emphasis on early black hole evolution and reproducing the high-z JWST AGN. The efficiency of high-redshift black hole growth significantly depends on assumed seeding and accretion models, with the widely used Bondi accretion model hindering the growth of lighter seeds. To address these limitations, we have developed a novel 'unified' AGN feedback accretion disc model, transitioning from an advection-dominated accretion flow (ADAF) at low Eddington ratios to a thin alpha disc at high Eddington ratios via a truncated disc configuration. Through various test cases using the moving mesh code AREPO, including single SMBHs in Seyfert galaxies' cores and SMBH binaries in gaseous discs, we demonstrate significant effects on luminosity distributions, with electromagnetic counterpart predictions being highly sensitive to the disc state. Additionally, the assumed disc model strongly influences the magnitude and orientation of supermassive black hole spins, with implications for future gravitational wave observatories like LISA and IPTA. These simulations emphasise the critical importance of accurately modeling SMBH accretion discs, as the disc state and spin evolution modulate accretion and jet powers, ultimately shaping the interaction between AGN and their host galaxies.
12:30
Lunch
Free afternoon
18:30
Dinner
Friday
Time
Speaker
Title
Chair: Johannes Buchner
09:15
Matthew Smith
The complex interplay between stellar feedback a
09:40
Filip Husko
AGN in the COLIBRE simulations
10:05
Alex Richings
Modelling synthetic emission line observations
Title: Modelling synthetic emission line observations to probe the physics of multiphase AGN outflows Abstract: Galaxies that host Active Galactic Nuclei (AGN) often exhibit fast outflows on kiloparsec scales, seen in molecular, neutral atomic and ionised gas. Modelling the emission and absorption lines from these different phases is crucial for understanding the nature of the outflowing gas and the relative importance of each phase. By comparing these predictions to observational data, we can also constrain our physical models for how the outflow is driven by the AGN. In this talk I will present radiative transfer calculations of infrared and optical emission lines from simulations of AGN outflows driven by a hot wind bubble to explore how these lines trace the physical properties of the multiphase gas. These simulations incorporate a time-dependent astrochemical model for the evolution of ions and molecules, which enables us to compute the line emission without needing to assume chemical equilibrium. I will show that, in these simulations, the thermal pressure of the hot bubble compresses the line-emitting gas to higher pressures than would be achieved through AGN radiation pressure alone. This produces observable signatures in certain line ratios such as [OIV]_25um/[NeII]_12um, [NeV]_12um/[NeII]_12um and [NIII]_57um/[NII]_122um that enable us to distinguish whether an AGN outflow is driven by thermal or radiation pressure. However, due to a period of rapid cooling in the outflowing shell after the initial post-shock phase, much of the line emission arises from gas that is out of pressure, thermal and/or chemical equilibrium. This highlights the importance of non-equilibrium modelling for predicting line emission from AGN outflows.
10:30
Coffee Break
Chair: Yi Zhang
11:10
Darshan Kakkad
JWST observations of hot molecular gas and P
Title: JWST observations of hot molecular gas and PAH emission at Cosmic noon Abstract: Growing supermassive black holes, known as Active Galactic Nuclei (AGN), are thought to play a crucial role in regulating star formation within their host galaxies. The feedback manifests in the form of radiation pressure-driven winds, outflows, and/or radio jets that expel or heat the molecular gas. AGN feedback is expected to be particularly significant during the epoch known as Cosmic Noon (1 < z < 3), when both the cosmic star formation rate and black hole accretion rate reached their peak. While observations increasingly reveal high-velocity outflows and tentative evidence of AGN-driven suppression and enhancement of star formation in isolated examples, the complex, multi-phase structure of the ISM and the effects of dust obscuration mean that our current understanding of AGN feedback remains incomplete.
In this talk, we present JWST/MIRI-MRS observations of hot molecular gas and polycyclic aromatic hydrocarbons (PAHs) in a sample of AGN host galaxies at Cosmic Noon. These hot molecular gas measurements complement ALMA submm spectroscopy, together providing a comprehensive view of how AGN influence the molecular gas content of their hosts. PAH emission serves as a tracer of obscured star formation, complementing ground-based near-IR Halpha observations. Our results indicate that AGN radiation predominantly excites the molecular gas to higher temperatures; however, the cold molecular gas reservoir continues to dominate the mass budget, implying a sustained capacity for star formation in these galaxies. We also detect strong PAH emission in several AGN hosts, suggesting that AGN-driven outflows have minimal impact on ongoing star formation. Overall, our results support a preventative feedback scenario, where the AGN represents a transitional phase in the evolutionary cycle of galaxies.
11:35
Hyunseop Choi
Broad Absorption-Line Quasars: Clearest Windo
Title: Broad Absorption-Line Quasars: Clearest Windows into AGN Outflows and Feedback across Cosmic Epochs Abstract:
One of the clearest observational signatures of AGN-driven outflows from the central SMBH is the presence of broad, blueshifted absorption lines (BAL) in quasar ultraviolet spectra. From the nearby universe to the Epoch of Reionization, BAL features from outflows with velocities reaching more than 10,000s km/s have been observed in a significant fraction of the quasar population. When their physical properties are constrained, these winds are often found to carry mass and energy far exceeding what is typically required for effective feedback.
In recent years, SimBAL has been instrumental in unveiling the physical properties of BAL outflows and quantifying their role in feedback across a wide range of redshifts. A study of a large sample of low-redshift iron low-ionization BAL (FeLoBAL) quasars revealed that BAL winds span over three orders of magnitude in their size scales, potentially impacting not only the nuclear regions of host galaxies but extending to circumgalactic scales. Combined with multi-wavelength observations, we have discovered robust evidence for multi-phase and multi-scale outflows in action in the early universe in a z~6.6 luminous LoBAL quasar.
With current and next-generation spectroscopy surveys (e.g., DESI, 4MOST), we expect to discover a large population of BAL quasars that have previously evaded our search, including those at z>5 and objects that are heavily absorbed or reddened. Ongoing work focuses on a comprehensive study of all types of BAL quasars at Cosmic Noon (z~2-3) and on newly identified LoBAL quasars at z > 5 from DESI, expanding our investigations to AGN-driven winds in the early universe. Finally, we are coordinating extensive multi-wavelength campaigns using NOEMA, and both ground- and space-based IFU facilities to investigate the multi-phase and multi-scale nature of BAL outflows and characterize their impact on host galaxies.
12:00
Discussion (Martin, Niany, Joseph)
12:30
Lunch
